【作者】 王丽丽；

【导师】 许湧深；

【作者基本信息】 天津大学 ， 应用化学， 2007， 博士

【摘要】 水介质中,以过硫酸钾(KPS)引发水溶性纤维素衍生物-羟丙基甲基纤维素(HPMC)与丙烯酸乙酯(EA)的无皂乳液接枝共聚合反应。其反应历程与常规乳液聚合的相似之处是,都经历了乳胶粒子的成核、增长和聚合完成阶段。考察了单体浓度、引发剂浓度、底物浓度、聚合反应温度以及第二单体的引入对接枝共聚合反应接枝参数的影响。在HPMC与KPS的预接触过程中,一方面,KPS热分解所生成的阴离子自由基能够导致HPMC大分子主链的氧化降解反应;另一方面,HPMC存在条件下,KPS的分解动力学表现出与纯水中一样的一级反应,但其分解速率常数比在纯水中提高到近7倍。第二功能性含氨单体甲基丙烯酸二甲氨基乙酯(DMAEMA)的引入,可以赋予接枝共聚物在模拟人工胃液中溶解的性能。当G为151.89%时,接枝共聚物包衣膜的抗吸湿性能与纯HPMC包衣膜相比提高了近5倍。以接枝共聚物乳液为骨架片粘合剂,制备KCl缓释片,当接枝率为59.29%、100.67%,乳液样品加入量为10%或20%时,KCl缓释片的累积释放量符合中国药典要求。此外,利用FTIR、NMR、TEM、SEM、XRD、DLS、DSC等表征技术对接枝共聚物的结构和形态进行了表征。分别采用预辐射及同步辐射技术成功实施了水介质中HPMC与EA的无皂乳液接枝共聚合反应。系统研究了辐射气氛、辐射总剂量、单体浓度以及聚合反应温度对体系接枝参数的影响。在相同的实验条件下,预辐射引发方法制备的接枝共聚物具有比同步辐射引发方法制得共聚物更高的接枝率值。随着接枝率的增加,接枝共聚物游离膜样品在模拟人工胃液中发生崩解所需的时间也延长。以羟丙基甲基纤维素与邻苯二甲酸酐的酯化反应制备了羟丙基甲基纤维素邻苯二甲酸酯(HPMCP)。在不使用有机溶剂的情况下,采用水乳化方法,成功制备了HPMCP的乳液水分散体。HPMCP乳液水分散体游离膜具有良好的成膜性能,且水分散体采用HPMC为乳化剂时,可以赋予游离膜材料优良的力学性能。苯甲酸甲酰基含量在28.17%~33.24%范围内的HPMCP水分散体游离膜样品,在模拟人工胃液中2小时内均不发生溶解,这符合药典中对于肠溶包衣材料的要求。HPMCP游离膜样品的溶解速率随HPMCP苯甲酸甲酰基含量的增加而增大;随释放介质pH值的增大而加快;随游离膜厚度的增加而有所减慢。更多还原

【Abstract】 Graft copolymerization of ethyl acrylate (EA) onto water-soluble cellulose derivative-hydroxypropyl methylcellulose (HPMC) was carried out with potassium persulfate (KPS) as initiator in an aqueous medium. The process of graft copolymerization was similar to that of classical emulsion polymerization, which can be divided into three stages: nucleation, growth, and polymerization finish. The effects of monomer concentration, initiator concentration, matrix concentration, reaction temperature, and the introducing of the second functional monomers in terms of the percentage of grafting (G) and grafting efficiency (GE) were investigated. The interactions between HPMC and KPS before the graft copolymerization process in aqueous system were also investigated. The results show that the specific viscosity of HPMC solution decreases significantly with increasing the interaction time, and KPS can lead to the oxide degradation of the main chain of HPMC macromolecules. On the other hand, decomposition rate of KPS shows first-order with respect to the concentration of KPS in the presence of HPMC, which is just the same as in pure water. However, the decomposition rate constant of KPS in the presence of HPMC is 7 times higher than that of in water at 60℃. Introducing the second functional monomer, dimethylaminoethyl methacrylate (DMAEMA), into the graft copolymerization can make the graft copolymer soluble in the simulated gastric fluid. The resistance moisture absorption property increases about 5 times with the higher G value 151.89%. The potassium chloride (KCl) slow release tablet is prepared by using the graft copolymer latex as the binding agent of the tablet. When G values are 59.29%, 100.67% and the added amount is 10% or 20%, the release properties of KCl slow release tablets satisfy the requirement of China pharmacopeia. In addition, the graft copolymers obtained were characterized by FTIR, NMR, TEM, SEM, XRD, DLS and DSC techniques.Graft copolymerization of EA onto HPMC backbone was also carried out usingγ-radiation (60Co) both by the preirradiation method and by the simultaneous irradiation method in the aqueous medium. The effects of radiation environment, radiation dose, monomer concentration and reaction temperature in terms of grafting parameters were investigated systematically. With the same experimental conditions, the grafting parameters of the graft copolymer preparaed by preirradiation irradiation method are higher than those of the samples prepared by simultaneous irradiation method. With increasing the G value, the disintegration time of free film sample is prolonged.Hydroxypropyl methylcellulose phthalate (HPMCP) was preparaed by the esterification reaction of HPMC and phthalic anhydride. And then, HPMCP obtained was used as the starting material to prepare HPMCP water dispersion by the water emulsion method, during which none of the organic solvent was used. The mechanical property of HPMCP water dispersion free film can be enhanced by using HPMC as the emulsifier. HPMCP water dispersion free film has the better film forming property, and HPMCP water dispersion free films with phthalyl contents ranging from 28.17% to 33.24% are all insoluble in the simulated gastric fluid within 2 hours, which meets the challenge of China pharmacopeia. The solution rate of HPMCP water dispersion free film can be accelerated with increasing the phthalyl content or the pH values of the release medium. Increasing the thickness of the free film makes the solution rate slower.更多还原